The present invention relates to a once daily unit dosage form comprising a combination of an antihistamine and a decongestant. The unit dosage form is useful in treating patients with colds, flu and other upper respiratory diseases.
Antihistamines include piperidinoalkanol derivatives which are disclosed in U.S. Pat. No. 4,996,061 and incorporated herein by reference. Piperidinoalkanol compounds are useful as antihistamines, antiallergy agents, and bronchodialators. Loratadine is a specific type of piperidinoalkanol and is disclosed in U.S. Pat. No. 4,282,233 as an antihistamine with little or no sedative effect.
Antihistamines are often administered in combination with sympathomimetic or decongestant drugs. Sympathomimetic drugs such as pseudoephedrine, phenylephrine and phenylpropanolamine are recognized by those skilled in the art as therapeutic agents effective for the relief of nasal congestion.
One common combination of antihistamine and sympathomimetic or decongestant is loratadine and pseudoephedrine. See for example U.S. Pat. No. 5,100,675 which is incorporated herein by reference. Loratadine and pseudoephedrine are sold commercially by Schering under the trade name CLARITIN® D24.
Once a day formulations containing a combination of loratadine and pseudoephedrine have been described. These once a day formulations have been undesirable for many reasons including deficiencies in safety, effectiveness and ease of manufacture. In order for a once a day formulation containing loratadine and pseudoephedrine to be effective it must provide a pseudoephedrine dissolution profile for periods longer than 12 hours without interfering with the safety and effectiveness of loratadine. A once a day formulation of loratadine and pseudoephedrine is described in U.S. Pat. No. 5,314,697. This formulation uses three specific polymers in the tablet core wherein the polymers must be present in specific amounts. This formulation further employs a wet granulate that must be dried. The use of multiple polymers in specified amounts and a wet granulate makes the manufacturing process of the tablets complex and time consuming.
It is an objective of the present invention to provide a safe and effective once a day dosage formulation containing both an antihistamine and a decongestant in which a tablet core can be directly compressed and is therefore easy to manufacture.
It is a further object of this present invention to provide a safe and effective once a day antihistamine and decongestant formulation which does not require a complex mixture of wetted polymers in the delayed release or matrix core of the formulation.